1. Field of the Invention
This invention relates to a composition for application to mucosal surfaces of the human body and, more particularly, to an oil-based composition for protecting against oxidant related tissue inflammation.
2. Discussion of the Related Art
Inflammation in the respiratory system related to tissue oxidant stress is common to a wide variety of airborne exposures and infections. Among well-described environmental exposures are the oxidant pollutants, ozone and nitrogen dioxide, ambient particulate matter, and cigarette smoke (1-6). Many acute and chronic inflammatory diseases of the airways are also associated with oxidant stress and include Chronic obstructive pulmonary disease (COPD), asthma, chronic sinusitis, viral and bacterial infections, and idiopathic pulmonary fibrosis (7-14). Evidence indicates that the upper respiratory system plays an important protective role in many of these types of challenges. In the case of chemical agents, this is achieved by the capture and neutralization of foreign agents in the inspired airstream, limiting their impact on lower airway structures (15). It has also been demonstrated that the nose can serve as a repository for inhaled viral and bacterial pathogens where they can be eliminated or held in check by immune defenses, thereby reducing the risk and/or severity of lower airway infections (16-19).
The effectiveness of the upper respiratory structures in carrying out these host defense activities would appear to depend, in part, upon their own antioxidant capabilities. However, little is known about mechanisms through which nasal antioxidant processes might be augmented and, if so, to what extent such augmentation would be effective as an intervention. As the primary cell of interface between the internal and external environments, the mucosal epithelial cell has long been the focus of much attention as a mediator of external stimuli and facilitator of both innate and acquired immune defenses in the respiratory tract (20, 21). Respiratory epithelial cells are known to initiate the release of a cascade of proinflammatory mediators through redox signaling (8, 22, 23). In addition, these cells have the capacity to exhibit up-regulation of very effective antioxidant defense mechanisms involving the secretion of decoy oxidant targets, as well as the synthesis of a broad spectrum of antioxidants (24, 25). Agents with the ability to enhance antioxidant pathways and interfere with proinflammatory signaling in the upper respiratory epithelial mucosa could enhance the protection afforded by these air passages.
The current studies were undertaken to determine if natural oils with purported antioxidant activities might represent a well-tolerated and potentially effective means through which to enhance inherent protective mechanisms in the nose. For these studies, the actions of a mixture of oils administered by aerosol spray were investigated in human subjects and in human epithelial cell culture systems. The goals were to determine the presence of abrogated pathophysiologic responsiveness in vivo in response to a controlled oxidant challenge in the nose and to develop an understanding of the mechanism through which such effects might be mediated.